1. Field of the Invention
The present invention relates to an insulating layer, and more particularly to a composite insulating layer capable of preventing electromagnetic interference and its manufacturing method.
2. Description of the Related Art
Electromagnetic radiation generated by advanced electronic products on the markets is mainly a high speed digital clock signal. Electromagnetic interference (EMI) may be generated in accordance with increased clock frequencies. It does not seriously interfere with communication, but can also influence the operation of other products in the environment to endanger human bodies potentially.
When a current passes through circuits of electronic components in an electronic product, an electromagnetic field is generated. The electromagnetic field irradiates outwards from electric wires. The magnetic field strength depends on the frequency and magnitude of the current. Surplus byproducts are so called EMI beyond the function required for any electronic circuit. In common knowledge, wireless communication devices, such as a mobile phone, may generate EMI. Further, electronic devices, such as personal computers, personal digital assistants, copy machines, scanners and digital cameras may also generate electromagnetic radiation during the operation process even if they are not radio frequency communication systems.
Since semiconductor technique and photography process are gradually advanced, the size of electronic components are greatly reduced. More and more transistors are placed into a central processing unit (CPU). To enhance the operation speed and processing efficiency of the CPU, pins of the CPU are increased. Consequently, when the CPU is operating, huge EMI is generated between pins. The EMI may influence the outside environment (including the operating adjacent to computers and the harm of human bodies).
Therefore, it lacks for an insulating layer capable of preventing electromagnetic interference to apply in the CPU.
Due to the EMI generated between the CPU pins in prior arts, a composite insulating layer capable of preventing electromagnetic wave and its manufacturing method are developed to effectively interfere with split electromagnetic wave generated by the CPU pins during the operation process, thereby preventing electromagnetic interference between pins and enhancing the stability of the CPU.